Yes, I am still having problems running the built in Disk Defragmenter. I have not yet tried the tools suggested in the replies above. I've been having other problems too, like PC is extremely slow most of the time, programs go non-responsive, PC freezes, PC goes to sleep (apparently) and can't be awakened unles I manually shot down, PC shuts down and restarts on it own.
I have been trying to research the subject and there are so many recommendations out there that I don't know what to do. I find it hard to believe that the built in defragmenter is no good and nobody what causes it to die. I am considering using Auslogic Disk Defrag Free.
Do you have a recommendation?